Nope, those look, well, not exactly, but quite like the worms from the original, so, don't think they're really ripping it from STO, maybe both artists drew from similar inspiration or something, or maybe there's only so much you can do with a giant death worm.
Not only that but the animations and everything about it (including that your fighting them in an arena in a hunting/ gladitorial competition) bear close resemblance to what we have in the STO episode of "Coliseum".
GW or for that matter ARENANET the studio - DID NOT, I repeat, DID NOT rip off anything from STO.
For starters GuildWars 2 has been in developmental way before the existence of STO - second, the worms were not inspired by STO, its more likely CRYPTIC was inspired by GuildWars or the movie DUNE.
In Guild Wars there were several versions of these worms, some small, some giants, and one rare one that was a Behemoth.
They existed in the dessert, and in the snow - GW:EN had Frost worms - pesty enemies that were a pain to beat.
More likely Tremors than Dune, in my opinion, but yeah... Guildwars had them long before STO. WoW and Mass Effect both had similarly styled worms long before STO. Hell Final Fantasy has them off and on at least as far back as VI. There's a short list of ways to make a worm fight an above-ground player, and even shorter when you want the worm to stay partially underground. You end up getting a lot of overlap.
Even if anyone did rip them off from STO, STO hasn't' exactly made prominent use of the ones it has.
If you did any mod for any major game you will soon realize it can be very difficult not to create similar things your fellow modders are making if you're all out to achieve something similar.
Just like in the modding world, there are people who just say, hey, great minds think alike, and there are others who send you cease and desist PMs first, and check who actually created the idea later. At other times a good idea is unfortunately ignored but someone necromances the thread 6 months later and posts an identical copy as his own
ps. Are the STO space armours inspired by Tron? Especially if you play a science character, the blue panels and EL lighting are TRON-ish.
The first time I remember seeing worms like this, (digging around underground, coming of through the earth) was in Dune... Nothing new about thing... (in fact a scene from Dune replayed for me in coliseum xD).
When it comes right down to it, I've seen most of what I've expirienced in STO so far in other games at least half a dozen times...